The graph illustrates how the total resistive force on a train changes as its speed changes. One part of this force comes from wheel friction, and this stays constant. The remaining part is caused by wind resistance. At a speed of $200\,\text{km h}^{-1}$, what is the ratio $\frac{\text{wind resistance}}{\text{wheel friction}}$?
- A4
- B5
- C8
- D10